The immunoregulation of rheumatoid factor by the CD8 T lymphocyte subset in rheumatoid arthritis.

Flow cytometric analysis on 81 peripheral blood samples from patients with rheumatoid arthritis (RA) showed that levels of serum IgM rheumatoid factor (RF) were associated with the CD8+ cell level. A significant elevation of natural killer (CD56) cell levels was also observed in RA peripheral blood. Using in vitro antibody production techniques, CD8+ cells from patients with RA appeared to act as suppressors of RF production. Paired blood and synovial fluid samples from 9 patients with RA indicated a significant increase in SF CD8+ cells and DR+ T cells over the corresponding peripheral blood levels. The data suggest that CD8+ cells in RA may respond to immunological abnormalities occurring during the course of the disease.